Valve mechanism for reciprocating fluid motors



May 5, 1953 H. T. DINKELKAMP 2,637,304

VALVE MECHANISM FOR RECIPROCATING FLUID MoToRs Filed Jan. 5, 1950 2SHEETS-SHEET l @k7/liege' H. T. DINKELKAMP VALVE MECHANISM FORRECIPROCATING FLUID MOTORS May 5, 1953 2 SHEETS- SHEET 2 Filed Jan. 5,195o M 6. 0 5 ,W Z no /M m! w wm 7%" 7 @2. a l A y@ fof W 0/ 2. Mw/ w,mw M, Y 00 J. M w M aw MM, 6 j M d Patented May 5, 1953 VALVE MECHANISMFOR RECIPROCATING FLUID MOTORS Henry T. Dinkelkamp, Chicago, Ill.,assignor to Stewart-Warner Corporation, Chicago, Ill., a corporation ofVirginia Application January 5, 1950, Serial No. 136,893

9 Claims. l My invention relates generally to fluid pressure operatedreciprocatingmotors, such as are used for the operation of grease pumpsfrom a compressed 'air supply.

' Some difficulty has been experiencedin devising a simplev and reliablereciprocating motor operable by compressed air for use as a part of alubricant pumping mechanism, even though lthe general principles ofoperation of such motors have been known for a long time. One of thedimculties encountered in the construction of motors of this type iscaused by the fact that when such motors are, connected ior theoperation of'a lubricant pump, the usual practice is to keep the pumpconnected to the source of compressed air continuously, and control theoperation of the pump solely by the means of the valve by which thedischarge of lubricant from the pump is controlled. Because of thenature of the load upon the reciprocating motor, and the manner in whichthe apparatus is customarily operated, it is essential that the motornot have any dead center positions and that it be capable' of operatingat various speeds. Because of these'factors, it is necessary that the.vD-slide valve, by which the supply of air to the' opposite ends of themotor cylinder is controlled,

'be operated without the benefit of inertia forces,

that vit be light in weight to enable it to be operated rapidly, andthat it be of very simple construction so that the motor will operatefor :longperiods of time without attention upon the part of the user.

It is therefore a primary object oi my invention to provide an improvedreciprocating fluid vpressure operated motor which is very simple inconstruction and operation, which may easily be serviced, which willoperate at any reasonable speed, which may be stopped and will restart"in any position in its operating cycle, and which may be economicallymanufactured.

A further object is to provide an improved and simplified spring togglemechanism forthe op eration of a D-slide valve. y

A further object is to provide an improved vreciprocating pneumaticmotor operated lubri- -cant pump in which the motor valve mechanism islocated between the motor cylinder and the lubricant pump so that thevalve mechae nism will be lubricated bywipage from the pump .pistonrod.

thereto.

upper end of the body Ill.

Other objects will be apparent from the following description, referencebeing had to the accompanying drawings, in which Fig. l is a sideelevational View of the motor with portions broken away to show parts ofthe spring toggle snap-over mechanism;

Fig. 2 is a central vertical sectional view of the motor, looking in adirection perpendiculal` to that of Fig. 1;

Fig. 3 is a horizontal sectional View, taken on the line 3 3 of Fig. 2;

Fig. 4 is an enlarged scale sectional view, taken on the line 4 4 ofFig. 2;

Fig. 5 is a fragmentary sectional view, taken on the line 5-5 of Fig. 4;

Fig. 6 is a central vertical sectional view of a modified form of theinvention; and

Fig. 7 is a horizontal sectional view, taken on the line 'I-I of Fig. 6.

The motor shown in Figs. 1 to 5 comprises a body It which may bemachined from cold rolled bar steel stock, and is secured toa suitablesupport I2. Threaded into the lower end ofthe body le is a lubricantpumping cylinder I4 having a piston actuating rod I6 secured Aself-aligning coupling I3 connects the pump piston rod I6 to a motorpiston rod 20 which is reciprocable in a bore 22, and the lower end ofwhich is suitably sealed by a packing gland 24, this packing including aperforated hollow cylinder pressure ring 2t and a washer 28thuspermitting lubricant to be forced from the cylinder I4 to a lubricantdischarge pipe 30.

The piston rod 2li has a piston 32 suitably secured to the upper endthereof, this piston rod being reciprocable in a cylinder bore 34 formedin a cup-shaped cap 3S threaded to the rlhe joint between the body Itand the wall of the bore 34 is sealed by an O-ring 38 preferably made ofa synthetic rubber material. Becaue of the use of this sealing ring, thecylinder cup 36 need not be tightly screwed to the end of the body I6.Instead, it

' may be screwed upon the body asuicient distance for the necessarymechanical strength of the joint into a position such that a threadedbow '44 'threaded in the pump body I0. Thus,

A no,V close .tolerances.are,required in the manulfacture of theseparts, and the assembly thereof is greatly facilitated.

The piston rod 28 is provided with an undercut shoulder 48 forengagement with a valve operator 43, and has a sleeve 50 clamped betweena second shoulder 52 and the piston 32. The sleeve U projects through asuitable packing gland 54, this gland comprising a V-grooved annularsealing washer 56 of synthetic rubber, which is backed by a leatherwasher 58, the two washers 58 and 58 being held in place by a retainingring 50 which is crimped to the packing bushing 62. The packing bushing82 is threaded in the upper end of the body lll and its joint therewithis sealed by a gasket 64. Y

A passageway 88 connects the lower end of the cylinder bore 34 to avalve port 'iii formed in a valve seat plate 14, this plate also havingports T2 and 'I3 formed therein. The port 'I2 is in communication withthe atmosphere through exhaust passageway lo, while the port 'i3communicates with the elbow e4 and thus with the upper end of thecylinder bore 34 through a passageway 18. i

-, As best shown in Fig, 3, the valve seat plate .has a raised valveseat surface Sii which may readily be ground and lapped so as to providea .smooth surface for engagement with a D-slide .valve 82. The valveseat plate 'i4 is tightly secured over the openings of the passageways558, 15, and i8 by a clamping plate Sli and a pair of cap screws 88which are threaded in the body Iii. The cap screws also hold in place agenerally U-shaped detent strip 8,8 which is perforated for thereception of the cap screws 86, andv which at its center has a, detentdimple Se formed therein, this dimple 90 being adapted to engage ineither oi two complementary grooves 92 and 93 (Fig. 5) which are formedin the adjacent surface of the D-slide valve B2. A perforated sheetgasket 94 is interposed between the valve seat plate 'I4 and the opposedsurface of the body ifi to seal the joint and make it unnecessary tofinish the adjacent surfaces of the body and valve seat -plate with anyhigh degree of accuracy.

The slide valve operatorv 48 is. freely slidable upon the piston rod 2,0between the shoulder 43 thereof and the lower end of the sleeve 5D, andis adapted to be shifted. by engagement with the shoudier 4e near thecompletion of the upward "Stroke ci the piston 32, and is adapted to beengaged by the, lower end of sleeve 5o near the completion of thedownward stroke of the piston. It will be noted that the operator 48 hasshoulders f S8 and Se near the ends thereof for engagement with theD-slide valve 82.

In order to secure rapid and reliable shifting v of the. D-slide valvebetween its two operative 1"positions, it is desirable to provide meansfor causing the operator 48 to shift between its two positions with amovement which is extremely rapid durmg the time that eithefnouider 9aor 99 of the operator is in contact with the D.slide valve 82,. Themeans for accomplishing thesnap cylindrical ends ft2 of a pair of togglelinks H34.

The opposite ends of the toggle linksy |04 have similar cylindricallyformed ends |06 which bear in4 semi--cylindrically shaped grooves whichextendv diametrically across the faces of plungers M8. The plungers 108slide freely in bores H0 formed, in hollow spring rx-:itainingv caps H2-which are threaded into the body l0 diametrically opposite each other.These plungers |08 are provided with vent openings ||4 so that theirmovement is not impeded by differences in pressure on the opposite sidesthereof and the plungers are urged toward each other by compressed coilsprings H6.

The valve chest H8 is formed by a radially extending bore which, afterassembly of the valve mechanism, is closed by a bushing t28 which isthreaded to receive a compressed air supply pipe 122. By virtue of thesize of the bore forming the valve chest I I8, the machining operationsfor the valve seat parts, including drilling, tapping, and facing, mayreadily be performed, so that the body i0 may be made out of cold rolledbar steel stock, and the cost of production considerably reduced.

Except when the lubricant pump is not to be used for an extended periodof time, air is con- I ing t28 into the valve chest H8.

. the operator 48. (see Fig. 5) must be equal to the The parts of thevalve mechanism and piston are shown in Fig. 2 in the position assumedby them immediately vfellowingvthe commencement of a down stroke of thepiston 3.2, for it will be noted that 4ports 'I3 are uncovered by the.D-slide walve'to permit flow of air under pressure to the. upper end ofthe power cylinder 34 while the lower end of said cylinder is vented tothe atmosphere through passageway 68, port '18, cavity in the D-slidevalve 82, porty 12, and passageway i8. It will be noted that the streamof air discharged from the passageway 'I6 is directed against the elbow44 and the elbow thus acts partially as a deflector to break up thestream.

Whenever lubricant is permitted to flow from the discharge pipe 35, thepiston 32 and all parts connectedl thereto,'wil1 move downwardly at arate determined mainly by the rateat which lubricant is being dispensed.When the lower end ef the sleeve 5i) engages the upper end of the valveoperator 48, it will carry the latter downwardly.v Thereafter theoperator will move downwardly with thev piston rod 20 until its shoulderS8 comes close to the upper surface Yof the Dvalve 82., for example,when the distance between the shoulder and the D-valve is aboutoneeighth of an inch. When the operator 43 has been moved to thisposition relative to the slide valve,v the toggle. links 104 will be, atdead center position so that the slightest additional downward movementof the operator 48 will permit the springs ILS to expand and snap thevoperator 48 downwardly with. a rapidly accelerating motion, so that whenthe shoulder 98 strikes the gagement with. the groove 92.

Inv order that the operation of the valve be'as above described, it isnecessary that there be. certainrelationships between the dimensionsvofthe parts of the valve mechanism; The throw T of sum of thev stroke Syof the D-valve 82, plus the clearance C betweenA the shoulder 98. andthe part of the, D-valve which it. engages, minusv P, the distancebetween the shoulder 99 andthe-other .surface of .the D-valve whichisengaged by the vlatter shoulder.' 4These dimensional relationships lmaybe set forth in the formula: T=C|S-P. Furthermore, the dimension Cshould be greater Lthan, or at least equal to, one-half the throw T ofthe operator 48, that is: CT/ 2.

When the slide valve operating vmechanism 'conforms to these dimensionalrelationships, the foperator 48 will strike its lower limit stop |30fbefore the D'valve 82 strikes the surface |32 of 'the retaining plate84, and the D-valve will com- 'plete its stroke due to its momentum,assisted by '-the action of the detent spring 88. f

When the D-valve 82 is in its lower position, air pressure is suppliedtothe lower end of the 4power cylinder 34 and the piston 32 will'commence its upward return stroke until the shoulder 46 on the pistonstem 20 engages the lower end of the operator 48 and carries the latterupwardly past v'the center of its stroke, when the vsprings ||6 will beeffective to snap the operator v48 through the remainder of its strokewhich is, of course, limited by the engagement of the operator with thelower end of the sleevelZ. Just after the operator 48 passes its centerposition, -its shoulder 99 will engage the D-valve 32 and snap thelatter upwardly vv-to its original position, the upward lstroke likewisebeing completed by -the momentum of the valve since there is preferably'slightfplay P between the shoulder' 99 when both the D-valve 82 andoperator 48 are -in their uppermost positions. By virtue of this -slightclearance or play P, the D-valve 82 is not required to bear the fullhammering impact due 'to the momentum of the operator 48 and the-actionof the valve is therefore more smooth and less-noisy with less wear onthe surfaces of the 4D-valve which are contacted by the shoulders 98.and 99.

`The invention may be embodied in a simplified rf-ormfor use in'smallerpumps to be manufactured at lower cost, as shown in Figs. 6 and 7. y.Inthis construction the D-valve and its seat, and the manner inwhich-these parts are held in position, are identical with thecorresponding parts previously described, and such-similar parts have`had similar. reference characters applied there- L'-to, andradescription thereof will not be repeated lsince the parts are identicalin function and opv'eration and differ only in size and details ofdesign. I

In Figs. 6 and 7, the D-valve is actuated by an operator |36Ywhich issimilar to the operator 48, except that it has but a single groove |38for ythe reception of the cylindrical end portion of a toggle link |40ywhich at its opposite end bears 'in a part cylindrical groove |4|'extending dia- -metrically across theface of a plunger |42. The

. `latter is guided for free movement in a cap |44 `and is forcedinwardly by a compressed coil spring |46. Air under pressure is admittedto the chest |48 through a fitting |50.

' Inasmuch asthe air supply connection to the upper end of the powercylinder |52 is at the Acenter thereof, this cylinder mai7 be threadedto the body |54 in the customary manner. In `other respects the form ofthe invention shown in Figs.

. .6 and 7 is the same as that described above with .reference to Figs.l to 5. In both embodiments,

.the body |54 is preferably made of solid cold -rolled bar stock, andthe various parts and pasxsageways are formed in this bar stock bysimple drilling, boring, reaming, and tapping operations,

,the arrangement of the parts being suchV that hiehdeereef accuracy ,islrequired so that 'the 'machining operations may be efficiently peiformed.

The cost of the. embodiment of Figs. 6 and 7 is reduced by virtue ofthefact that but one spring pressed plunger is used, and because most ofthe-other parts are smaller and lighter. Its

operation is, however, substantially the same as that of the embodimentshown in Figs. 1 to 5.

In both embodiments ofV the invention, the

D-valve is made as small and as light in Weight as is practical, so thatit may be operated very rapidly. In both forms of the invention theoperating parts are easily accessible for inspection and replacement,and the valve, valve seat, and the packing glands, which are the partsmost likely to require replacement due to wear, are small and easilyreplaced.

By virtue of the fact that the valve mechanism is positioned-between theair cylinder and the 'lubricant cylinder, lubricant adhering to thepiston rod 20, so called wipage, will pass into `the 'valve chest andlubricate all of the moving parts therein. Some of this lubricant willflow with the air to the motor cylinder and lubricate the parts movingtherein. By thus locating the valve between the pump and the motor, thenecessity for complicated operating connections be,- tween the pistonrod and the valve mechanism #is avoided. Furthermore, the arrangement ofare combined into a single part, thus further reducing the cost oftheunit.

While I have shown and described preferred embodiments of my invention,it will be apparent that numerousA variations and modifications theerofmaybe made without departing from -the underlying principles of theinvention. `I

therefore desire, by the following claims, to include within the scopeof the invention all such variations and modifications by whichsubstantially the results of my invention may be ob- *tained through theuse of substantially the same or equivalent means'. I

' I claim:

y1. A valve mechanism for a iiuid'pressure operated motor which includesa reciprocating 'piston rod having a pair of spaced stops, com- 55vvalve seat surface portion and having three ports in the `seat surface,a two-position D-slide valve vhaving a pair of transverse groovestherein, a retainer for the valve seat memberihaving an prising, a valveseat member havingV a raised opening for the raised valve seat surfaceportion thereof and of sufficient thickness to form a -the stopsthereof, said operator having parts thereof engageable with the valve tomove the latter between its two operative positions, the

spacing of ythe 'parts being much Vgreater than the spacing of thesurfaces of the valve engaged by the parts, and a quick snap-overrmechanism Connected to said operator.

2. A D-slide valve structure comprising a body .having adjacentpassageways therein, a valve seat plate positioned overthe ends ofthepassageways :and having aligned' ports respectively in communicationwith the passageways, said Aplate having a ridge forming azvalveseat'surface, a two-position D-slide valve reciprocable .over the valveseatfand `having an irregularity in its surface spaced from the .seatsurface, a resilient detent member having a part cooperable with .theirregularity in the slide valve to hold :the latter in either of its twooperative positions, .a clamping plate having an opening receiving theraised portion.- of the ,valve seat plate and forming. stops to limitthe stroke' of the' slide valve, means to secure the clamping plate to.the body, and a .reciprocatory operator having a snap actionoperablenear the ends of its stroke to.. engage vthe slide valve andmove it rapidly between its operative positions.

..3...AYD-slide valve structure comprising a body having. adjacentpassageways therein, a valve .seat vplate,'positioned over the ends ofthe pas- :plate and forming stops to limit the stroke of -theslidevalvameans to secure the clamping :plate to the body, and a reciprocatorysnap action operator operable 'after it has passed the :center of 'itsstroke to engage the slide valve ,and kmove .it rapidlybetween itsoperative positions. 1 n

u 4. Avalve mechanism for a, fluid pressure operatedmotor which includesa reciprocating piston rod, comprising a ,valveV seat member havingftlnee ports in the seat surface, amro-position .iD-slide valvecooperable with the valve seat, a .spring detent cooperable with thevalveto hold lthe latter in either of its positions, a valve opieratorhaving parts thereof engageable with the valve to move the latterbetween its two opera.- :tive positions, the spacing of the parts beingVmuch greater than the spacing of the surfaces -o the valve engaged bythe parts, means mov- :ingwith the piston rod to engage and move theoperator near the ends of the strokes of the piston rod, a springpressed plunger movable in a direction perpendicular tothe movement ofthe ioperator, and a toggle link having its ends pivotr-ally-connectedto the plunger and to the operator respectively.

:a i 5. A D-slide valve structure comprising a body fhaving adjacentpassageways therein, a valve .iseatplate positioned over the endsof"'the paszsageways and having aligned ports respectively incommunication with the passageways, said vplate having a ridge forming avalve seat sur- Iiace, a D-slidevalve vreciprocable over the valve seat,a clamping plate having an opening re- -ceiving the raised portion ofthe valve seat plate and forming a guide and stops to limit the strokelof-the slide valve, a resilient detent element en- 'gageable with theslide valve to hold it in either 'fofv two positions, and means vtosecure both the fdetent element and the clamping plate to the :body:

6. A valve mechanism for a iluid pressure operated motor which includesa reciprocating pis- 'L-.ton ro d,'comprising a valve seat member havingthree-ports in theseat surface, a two-position "I5-slide valvecooperable withr the valve seat. a

spring detent cooperable with the valve to hold the latter in either ofits positions, a valve operator having parts thereof engageable withthevalve to move the latter betweenv its two operitive positions, thespacing of the parts being much greater than the spacing of the surfaceslof the valve engaged by the parts. means moving with the piston rodtoengage and move the operator near the ends of the strokes ofthe lpistonrod, a pair -of vspring pressed plungers movable in a directionperpendicular to the movement of the operator, and toggle links'havingtheir ends pivotally connected to the plungers andato Athe operatorrespectively. f-

7. A D-slide valve structure comprising a body having adjacentpassageways therein. av valve seat plate positioned over the ends of thepassageways and having aligned ports respectively in communication withthe passageways, said plate having -a ridge forming a lvalve seat'surface, a D-slide valve reciprocable over the valve seat surface andhaving two operative positions, a resilient detent cooperable with theslide valve to hold the latter in either of its two operative positions,a unitary clamping and valve guide plate having an opening receiving theraised portion of the valve seat plate and formingr a guide and stops tolimit the stroke of the slide valve, means to secure the clamping plateand detent to the body, and a reciprocatory snap action operatoroperable after it has passed the center of its stroke to engage theslidevalve-and move it rapidly between its operative positions.

8. A valve mechanism for a fluid pressure operated motor which includesav reciprocating piston, comprising, a valve seat member having a raisedvalve seat surface portion and having three ports in the seat surface, atwo-position D-slide valve having a pair of transverse grooves therein,a retainer for the valve seatmember having an opening for the raisedvalveseat surface 4portion thereof and of suilicient thickness to form aguide and end stops for the valve, a spring detent cooperable with thegrooves of the 4valve to hold the latter in either Yof its positions, avalve operator, actuating means moved by the piston and engaging theoperator 'near the ends of the stroke of the piston, said voperatorhaving parts engageable with the lvalve -to move the latter between itstwo operative positions, the spacing of the parts being much greaterthan the spacing of the surfaces ofthe vand having aligned portsrespectively in communication with the passageways, said plate having aridge forming a valve seat surface. a two-position D-slide valvereciprocable over the valve seat and having an irregularity in itssurface spaced from theseat surface, ar resilient detent member having apart cooperable with the irregularity in the slidevalve to holdV thelatter in either of its two operative positions, a clamping plate havingan opening receiving the raised portion of the valve seat plate andforming stops to limit the stroke of the slide valve, means to securethe resilient detent and clamping plate to the body, a reciprocatoryoperator, and resilient means to cause the operator after it has passedthe center of its stroke, said operator being conformed to engage theslide valve and move it rapidly between its vq jlperative positions onlyafter the operator has moved past the center of its stroke.

HENRY T. DINKELNAMP.

References Cited in the le of this Ypattern'.

UNITED STATES PATENTS Number Name Date 1,352,504 Folberth Sept.g14, 19201,841,634 Rolstad Jan-,19, 1932 1,943,603 Hartman Jan. 16, 1934 Number

